Gas turbine engine with structure for directing compressed air on a blade ring

A gas turbine engine comprising:

• a compressor for generating compressed air;
• a turbine comprising:
• a plurality of rows of vanes;
• a plurality of rows of rotatable blades;
• at least one static structure comprising a blade ring surrounding a corresponding row of vanes and a corresponding row of blades, each of said vanes of said corresponding row of vanes comprising a cooling passage, and said blade ring including at least one opening for communicating with said cooling passages of said corresponding row of vanes;
• said blade ring including upstream and downstream ends defining respective vertical blade ring surfaces, said vertical blade ring surfaces extending radially outward to an engagement of said blade ring with an inner surface of a turbine casing surrounding said blade ring;
• and
• fluid structure for receiving compressed air from the compressor and extending toward said stationary blade ring for discharging the compressed air directly against at least one of said vertical blade ring surfaces of said blade ring such that the compressed air impinges on said at least one vertical blade ring surface and then passes through said at least one opening in said stationary blade ring and into said cooling passages of said corresponding row of vanes, said fluid structure comprising at least one impingement pipe located adjacent said at least one vertical blade ring surface and including a plurality of openings positioned so as to direct the compressed air toward said at least one vertical blade ring surface.

A process for operating a gas turbine engine wherein the gas turbine engine comprises:

• a compressor for generating compressed air, wherein the compressed air increases in temperature from ambient when the gas turbine engine begins operation to an elevated temperature;
• a turbine comprising:
• a plurality of rows of vanes;
• a plurality of rows of rotatable blades;
• at least one static structure comprising a blade ring surrounding a corresponding row of vanes and a corresponding row of blades;
• said blade ring including upstream and downstream ends defining respective vertical blade ring surfaces, said vertical blade ring surfaces extending radially outward to an engagement of said blade ring with an inner surface of a turbine casing surrounding said blade ring;
• and
• fluid structure for receiving compressed air from the compressor and extending toward said one stationary blade ring for discharging the compressed air directly against at least one of said vertical blade ring surfaces of said blade ring at least during an initial startup period of said gas turbine engine such that the compressed air impinges on said at least on vertical blade ring surface, said fluid structure comprising at least one impingement pipe located adjacent said at least one vertical blade ring surface and including a plurality of openings positioned so as to discharge the compressed air toward said at least one vertical blade ring surface;
• the process comprising:
• discharging compressed air directly against the vertical blade ring surface of said blade ring at least during the initial startup period of the gas turbine engine such that the compressed air impinges on said vertical blade ring surface so as to increase the temperature of said vertical blade ring surface.